The jury is still out on how tropical storms will change as climate warms, but rising sea levels will almost certainly place more coastal property at risk of flooding, says a team of scientists writing in the journal Nature.

In the northern hemisphere, ice sheets ebb and flow in 100,000-year cycles, driven by varying amounts of sunlight falling on Earth’s surface as its orbit and orientation toward the sun changes. But astronomical variations alone cannot explain why ice ages develop gradually but end quickly, in a few thousand years. Though the last ice age saw several peak-periods of sunlight, it was the last one—about 10,000 years ago—that caused the ice to withdraw from much of Europe and North America.

The seas are creeping higher as the planet warms, but scientists have not yet reached a consensus about how high they may go. Projections for the year 2100 range from inches to several feet, or more. The sub-tropical islands of Bermuda and the Bahamas contain important sites where researchers have gone looking for answers. By pinpointing where shorelines stood on cliffs and reefs there during an extremely warm period 400,000 years ago, they hope to narrow the range of global sea-level projections for the future.

The seas are rising, as they have during past periods of warming in earth’s history. Estimates of how high they will go in the next few thousand years range from five meters, putting greater Miami underwater, to 40 meters, wiping most of Florida off the map. “The range of estimates is huge to the point of meaninglessness,” says

Scientists aboard the research ship the JOIDES Resolution recently drilled two kilometers into Earth’s crust, setting a new record for the deepest hole drilled through the seafloor on a single expedition.

A new study of sea level fluctuations over the last 22,000 years is the latest to predict that rising seas could reach close to one meter by the end of this century, consistent with the most recent sea level projections made by the Intergovernmental Panel on Climate Change (IPCC).